1. Field of the Invention
The present invention relates to a method for producing thermosets from oils, and more particularly, the present invention relates to a method for producing rubbery and glassy thermoset polymer resins via ring-opening metathesis polymerization of functionalized oils, which oils are derived from renewable feedstocks.
2. Background of the Invention
Petroleum is used in the manufacture of fuels, lubricants, fertilizers and plastics. In the United States, oil supplies about 40 percent of all the energy that the country consumes. Only about half of the oil consumed in the U.S. is actually produced here. This nation's continuous importation of petroleum comes at a significant cost economically and to our national security.
The environmental impacts of the continuous use of petroleum-based products also are significant. For example, current plastics are based in large part on olefins, such as ethylene, acrylates and acrylonitrile. The resulting materials are virtually indestructible in landfills. Also the petroleum-based plastics industry is quite energy intensive, since fossil fuels require, considerable processing before they can be used to make final commercial products.
With the tremendous commercial importance of the polymer industry, it is obvious that even the partial replacement of petroleum-based materials with useful, new biomaterials from renewable, agricultural resources, like agricultural-based oils (e.g., soy, corn and linseed oils) and aquatic based oils (fish, plant life etc.), will have not only a tremendous impact energy-wise, but also economically and environmentally. Economically, there is a significant benefit when one considers that about 60 billion pounds of synthetic polymers are produced annually in the U.S. alone. Vegetable oils are natural, renewable and cost only about half what most petroleum starting materials cost. Replacing only a fraction of the petroleum-based: starting materials by less expensive natural'oils will result in major cost reductions in the ensuing products.
Lately, increased interest in the production of plastics and rubbers from renewable and sustainable feedstocks has been driven by high and unstable petroleum prices and uncertainties as to how long petroleum supplies can last.
Most research on environmentally-friendly plastics has focused on using carbohydrates and proteins, while very little work has been done using natural oils and fats. The majority of work with agricultural oils has employed relatively expensive functionally-substituted oils or costly derivatives of the cheaper agricultural oils, thus diminishing one of the major economic advantages of using biorenewables to prepare plastics. For example, the photo-initiated cationic polymerization of epoxidized soy, linseed and castor oils has been carried out, but no properties or utility for the resulting polymers have been reported. Chakrapani, S.; Crivello, J. V., “Synthesis and Photoinitiated Cationic Polymerization of Epoxidized Castor Oil and its Derivatives,” Macromol. Sci.-Pure Appl. Chem. A35 (1998) 1-20.
A great deal of attention has been focused on the production of ethanol from cellulosics and biodiesel from vegetable oil; as discussed in Johnson, J. Chem. Eng. News. 2006, Vol 84, Issue 35, p 13; and Knoth, G. J. Am. Oil Chem. Soc. 2006, 83, p 823.
Vegetable oils are a very promising renewable feedstock for polymer synthesis as either the triglyceride oil itself or derivatives thereof. Research has focused on either condensation or free radical polymerization to produce thermosetting resins. Petrovic, Z. S.; Wei, Z.; Javni, I. Biomacromolecules 2005, 6, 713; Mosiewicki, M.; Aranguren, M. I.; Borrajo, J. Appl. Poly. Sci. 2005, 97, 825.; Cakmakli, B.; Hazer, B.; Tekin, I. O.; Kizgut, S.; Kosal, M.; Menceloglu, Y. Macromol. Biosci. 2004, 4, 649; and LaScalia, J.; Wool, R. R Polymer 2005, 46, 61.
A need exists in the art for a method for producing thermoset resins from renewable feedstocks. The method should yield rubbery resins with glass transition temperatures as low as −30° C., and glassy resins with glass transition temperatures as high as 100° C. Also, the method should utilize well known plant, animal, and mineral oils requiring little modification. Lastly, the method should require neither elaborate equipment nor temperatures above 150° C. to effectuate.